1. Field of the Invention
The present invention relates to a vein imaging apparatus and a thumbnail image creation method.
2. Description of the Related Art
Biometric personal authentication is critically important technology for safeguarding the rights in the future network society. Particularly, in Internet commercial transactions where theft of money, contents, rights or the like via Internet is possible by means of spoofing by a third party, the biometric personal authentication attracts attention as technology for safeguarding the area that is insoluble with cryptograph only. Fingerprint or iris authentication, however, has the issue of forgery remaining unsolved. On the other hand, personal authentication technology that uses a vein pattern in a part which is difficult to be imaged from the outside is expected to be next-generation biometric personal authentication for its high verification accuracy and high difficulty of forgery or spoofing.
Examples of such biometric personal authentication technology are fingerprint authentication technology and vein authentication technology. While the fingerprint authentication technology has a problem in the existence of unregisterable users (about 4%), resistance to spoofing attacks using a residual fingerprint or the like, it has an advantage of reducing a sensor size because it allows easy image composition with a scan type using a line sensor, an area sensor or the like. On the other hand, the vein authentication technology, which is expected to be next-generation authentication technology having less problem, has been difficult to be mounted on mobile equipment or the like due to a large sensor, and, particularly, it has been difficult to form a device in a planar structure in an imaging scheme that uses a vein transmitted image due to a strict restriction on the position of a light source.
In order to achieve size reduction of a device using the vein authentication technology, Japanese Unexamined Patent Publication No. 2008-36058 discloses a technique of using a microlens array in which microlenses are arranged in an array.